Improvement in the manufacture op paper pulp



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ASAHEL K. EATON, OF PIERMONTQNEW YORK.

Letters Patent No. 106,143,1lated August 9, 1870.

IMPROVEMENT IN THE ANUFACTURE or' PAPER PULP.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern Be it kuon'n that I, ASAHEL K. EATON, ofPiermont, in the county of Rockland and State of New York, have inventedcertain new and useful Improvementsin the Art of Manufacturing PaperPulp from,

Straw, \Vood, and other Vegetable Fiber; and 1 do hereby declarethefollowing to be such a full, clear, and exact description thereof aswill enable any one skilled in the art to which myinvention appertaiusto \vorkor practice the same. i

In the manufacture of paper pulp after the process described in thepatent heretofore granted to nie, and dated the 22d of March, 1864, itis necessary to reproduce the caustic, soda, or potash toinsure thedesired profit as the oonnnercial result of the process, but the expenseof apparatus and labor necessary to thereprmluction of the. soda orpotash makes it desh-able to substitutein its place a solvent, therecovery whereof is urmecessary to insure at least as large a profit asan be obtained in the use of soda or potash as a solvent, even thoughthewhole of it contained in the refuse water he recovered, which isscarcely possiblc in the practical marmthctureof the pulp.

Now, 1 have discovered that the incrustiug matter of the, cellulose ofthe wood, straw, orother vegetable material suitable for paper pulp, canbedissolved readily, and with great economy, by the use of oxysulphideof calcium, a substaucept' such little cost that the refuse liquor canbe thrown away without material loss to the maimfitoturcr.

In the practiceof this improvement, I first put the straw, wood,'.orother tibrous'sub stance out of which the pulp is to be made, in thewater-tank, and raise it to the boiling point. I then take, to a ton ofstraw or wood, from two to five hundred pounds of lime, which ltirstmakeinto a milk of lime. To this I add about twenty pounds of sulphur".I then throw the mixture into the tank of boiling water containing thestraw or wood, leaving the-combination of the sulphur and lime to takeplace in the tank, thus saving the preparation of the sulphidebeforehand, and continue the treatment as though a caustic sodawere'uscd.

The result is apulp in all respects equal, if not superior, to that madeby the use of caustic soda or pot-ash, and in evena morefiworablecondition for bleachin The proportions given above may, of course, besomewhat varied, as will appear by those given, but, the lime shouldalways be in chen'iical excess of the sulphur, that is, more than isnecessary for the sul-. phur to combine with to form the sulphideof-calcinm, the ordinary quantity of water being used in all cases.

The rationale of the process seems to be as follows: The sulphide formedin the solution first dissolves the resinous and incrusting matter ofthe straw or wood, which it immediately gives up to the excess of lime,the sulphide being thus left in itsoriginal condition to act again andagain.

In referring to the patent heretofore granted to me, I do not intend tolimitthis improvement to the method described there, as this .sulphidecan be substituted anthe caustic alkali in-all processes where the sameis usedas :a solvent with beneficial and economical results; tlucos'toftreating tiber with alkali after the old process being from two tothree centsper pound of pulp produced'tbr the alkaline treatment alone,while by the use of the sulphide the cost will be very much reduced,even by the old process; and, in connection with the process describedin the patent above referred to, the cost is reduced to one-half cent orless per pound of pulp for this part of the process, Wbiclnitselhis agreat advantage eoasideredmerely in the light of commerce.

Having now described the nature and extent of my improvementin the artof manufacturing paper pulp,

Iclailn as new herein, auddesire to secure by Lettors Patentv The use ofoxysulphide otcalcinm as a solvent in the manufacture of paper pulp fromstraw, wood, or other vegetable substance suitable for that purpose.

A. K. EATON. Witnesses:

Anos Bnoam'ax, PETER D. Knxsv.

